1. Field of the Invention
The present invention relates to a dehumidifying apparatus with an electronic refrigeration unit utilizing heat-absorbing-type and heat liberating-type reactions based on Peltier effect produced at the junction between an N-type thermoelectric element consisting of N-type semiconductor and a P-type thermoelectric element consisting of P-type semiconductor.
2. Description of the Related Art
It is considered to form a dehumidifying apparatus with a thermoelectric conversion unit consisting of N-and P-type thermoelectric elements. FIG. 34 shows a thermoelectric conversion unit to be applied to the above dehumidifying apparatus, having a plurality of N-type thermoelectric elements 111, 112, . . . consisting of N-type semiconductor and P-type thermoelectric elements 121, 122, . . . consisting of P-type semiconductor which are linearly arranged by turns at a certain interval. These arranged N-type thermoelectric elements 111, 112, . . . and P-type thermoelectric elements 121, 122, . . . are successively connected at their top and bottom in series by heat-absorbing-type electrodes 131, 132, . . . and heat-liberating-type electrodes 141, 142, . . . .
That is, when a DC power source is connected to a group of the serially-connected thermoelectric conversion elements, heat absorbing reaction occurs at the heat-absorbing-type electrodes 131, 132, . . . constituting the NP junction and heat liberating reaction occurs at the heat-liberating-type electrodes 141, 142, . . . constituting the PN junction, in the current flowing direction because of Peltier effect.
Insulating plates 15 and 16 are installed so that they are faced each other on the surfaces where the heat-absorbing-type electrodes 131, 132, . . . and heat-liberating-type electrodes 141, 142, . . . are set, in order to hold the groups of thermoelectric conversion elements. And, an absorbing heat exchanger 17 and liberating heat exchanger 18 are installed outside the insulating plates 15 and 16 so that the exchangers are faced each other.
For the thermoelectric conversion unit with the above structure, the temperature decreases at the heat-absorbing-type electrodes 131, 132, . . . and the low temperature is transmitted to the absorbing heat exchanger 17 through the insulating plate 15, while the temperature rises at the heat liberating-type elements 141, 142, . . . and the high temperature is transmitted to the liberating heat exchanger 18 through the insulating plate 16. Therefore, heat absorbing and heat liberating effects are always taken out through the insulating plates 15 and 16 and the absorbing and liberating efficiencies are greatly decreased by the insulating plates 15 and 16.
For a dehumidifying apparatus consisting of the above thermoelectric unit, the air dehumidified and cooled by the absorbing heat exchanger 17 is sent to the liberating heat exchanger 18 to be heated. Therefore, the size of an heat liberating fin installed on the liberating heat exchanger 18 increases. In this case, because the insulating plate 16 is set between the heat-liberating-type electrodes 141, 142, . . . producing liberating effect and the liberating heat exchanger 18, the thermoelectric conversion effect decreases. Therefore, to obtain adequate dehumidifying effect, the size of the thermoelectric conversion unit must be increased.